Understanding New Pulse-analysis Techniques

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1 Understanding New Pulse-analysis Techniques Giuseppe Savoia Keysight Technologies Aerospace Defense Symposium

2 Agenda Concept for Radar/Pulse signal analysis AD Symposium Page 2 Vector signal analyzers and oscilloscopes to be compared Characteristics of Radar/Pulse signal Measurement considerations Overcome challenges of complex pulse analysis How to identify the signal immediately? How to acquire wideband signal with best fidelity? How to improve acquisition efficiency? How to characterize pulse modulation? Summary

3 Vector Signal Analyzers and Oscilloscopes to be Compared Which platform should I choose? UXA Signal Analyzer 510 MHz BW, 14 bits Will see that new vector signal analyzers have increased their analysis bandwidth and they offer the best dynamic range Will see that new oscilloscopes offer bandwidths typically wider than a vector signal analyzer, with good amplitude and phase linearity, and useful, but lower dynamic range S-Series Oscilloscopes 8 GHz BW, 10 bits This presentation will apply both platforms to pulsed RF analysis measurement challenges and compare results AD Symposium Page 3

Concept for Radar/Pulse Signal Analysis Characteristics of

Radar Complex modulation is often used for inpulse modulation -

Coded (ZC Code, Frank) - Poly Time, PRN Frequency hopping

4 Concept for Radar/Pulse Signal Analysis Characteristics of Radar/Pulse signal Pulse modulation is basic format for Military Radar Complex modulation is often used for inpulse modulation - CW Pulse, LFM, NLFM - Binary Phase Coded (Barker) - Poly Phase Coded (ZC Code, Frank) - Poly Time, PRN Frequency hopping Variable Pulse Repetition Interval (PRI ) High dynamic range AD Symposium Page 4

5 UXG Agile Signal Generator 20 and 40 GHz options For high-speed, low phase noise, multi-port applications 200 ns update rate Phase repeatable or phase continuous frequency switching Two Amplitude Ranges 10 dbm LO -120 to 0 dbm (90 db agile) 10-25% Linear Chirp Widths Arbitrary Chirp Profiles Pulse ~6 ns Rise/ Fall Pulses, 90 db on/off -70 dbc GHz Industry leading phase noise GHz Multiple Instrument Coherence Frequency Range Output Power Agile Amplitude Switching Range Agile Amplitude Switching Range Phase Noise (10 20 khz offset (typical) Non-harmonic Spurious Digital word control 0.01 to 20/40 GHz + 10 dbm 80 db < 0 dbm 20 GHz Model Only 10 db >0 dbm -126 dbc/hz -70 dbc Frequency, FM/PM Lower cost of ownership Industry s best reliability with a target MTBF of 75k hours Compatibility mode Pulse On/Off Minimum Pulse Width Size Comstron 90 db 5nS 3U AD Symposium Page 5

6 UXG - Enabling Technologies UXG Agile Signal Generator 200 ns Update Rate nanofet MMIC switches & attenuators Proprietary DAC Phase Coherent Switching AD Symposium Page 6

7 N5193A UXG Agile Signal Generator Lowpass Filter Bands Numerically Controlled Oscillator Digital to Analog Converter Freq Doublers x2 n Amplifier Electronic & Mechanical Attenuators Analog Out GHz Frequency Phase LFM Pulse Pulse Time Pulse Width Pulse Parameter List & External Digital PDW Interface Amplitude PDWs from simulation computer AD Symposium Page 7

8 Pulse Interleaving Big Bird 1 Big Bird 2 Big Bird 3 Collisions Output Emitter Priority t-time AD Symposium Page 8

9 Multiple Instrument Synchronization Simulate AoA Exercise direction finding receivers Play any pulse out of any emitter on any channel to increase pulse density UXG UXG UXG UXG AD Symposium Page 9

Modulation Characteristics(Frequency/Phase/Time) Analysis Length (Memory Size)

10 Concept for Radar/Pulse Signal Analysis Measurement considerations Frequency Band Signal Bandwidth Dynamic Range Measurements - Power - Spectrum - Modulation Characteristics(Frequency/Phase/Time) Analysis Length (Memory Size) - Long scenario with variable pulse parameters - Low duty cycle pulses AD Symposium Page 10

11 Agenda Concept for Radar/Pulse signal analysis Characteristics of Radar/Pulse signal Measurement considerations AD Symposium Page 11 Overcome challenges of complex pulse analysis How to identify the signal immediately? How to acquire wideband signal with best fidelity? How to improve acquisition efficiency? How to characterize pulse modulation? Summary

Overcome Challenges of Complex Pulse Analysis General procedure for pulse signal analysis DUT Acquisition HW Analysis Algorithm Streaming for Post Analysis Data

12 Overcome Challenges of Complex Pulse Analysis General procedure for pulse signal analysis DUT Acquisition HW Analysis Algorithm Streaming for Post Analysis Data Storage Live Measurement Display Real-Time Analysis Trigger Complex Pulse Signals Trigger & Acquisition Measurement Processed Results Shown AD Symposium Page 12

input signal is varying in amplitude and Mag conditions are met.

13 How to Identify the Signal Immediately? Real-time Trigger Real-time trigger used for pulse signal identification IF Mag Trigger Trigger happens when input signal is varying in amplitude and Mag conditions are met. A good start to trigger pulse measurement Could be used with Holdoff to get a stable measurement No frequency selectivity, can t trigger specific frequency event Question: How to avoid triggering by unwanted signals? AD Symposium Page 13

Based on RTSA HW Various criteria for Trigger: Enter, Leave, Inside, Outside, Enter Leave, Leave Enter Identify specific

14 How to Identify the Signal Immediately? Real-time Trigger Real-time trigger in signal analyzer used for pulse signal identification Frequency-Mask Trigger (FMT) Based on RTSA HW Various criteria for Trigger: Enter, Leave, Inside, Outside, Enter Leave, Leave Enter Identify specific frequency pulse from complex environment Can be recalled in VSA for seamless pulse analysis Question: How to identify a pulse in presence of other signals with similar frequency? AD Symposium Page 14

15 Amplitude Amplitude Amplitude How to Identify the Signal Immediately? Real-time Trigger Real-time trigger used for pulse signal identification Time Qualified Triggering(TQT) FMT (?) Frequency 5 GHz band FMT does not work if equal amplitude signals overlap in the frequency domain Frequency Time BUT, overlapping signals in the frequency domain can be resolved by time domain trigger. Use case: To trigger on a pulsed signal in presence of other similar signals that lasts for either longer or shorter durations AD Symposium Page 15

16 Amplitude Amplitude How to Identify the Signal Immediately? Real-time Trigger Time Qualified Triggering(TQT) Qualifying a trigger by using a time criteria Available with FMT and IF Mag triggers Trigger point definition Data acquisition happens AFTER time criteria has been applied Use pre-trigger to capture the entire event >T1 (trigger on blue pulse) Trigger Point Overlap in frequency resolved! T1 Time Frequency AD Symposium Page 16

17 I Can t See My Pulse from Others!! Demo video available on DVD TQ>20us FM Chirp Two pulses at similar frequency TQ<20us CW Pulse AD Symposium Page 17

18 I Can t Trigger On My Signal from Environment!! Demo video available on DVD TQ>300uS Isolate ZigBee FMT without TQT cannot separate signals TQ<300uS Isolate Wifi AD Symposium Page 18

Oscilloscope Has Time Holdoff or Zone Trigger for Stable Trace Holdoff set > widest pulse;

signal crosses a voltage threshold Slope specified Holdoff set to be a longer time than

use Zone triggering --- define area where signal trace ignored if the trace passes through

19 Oscilloscope Has Time Holdoff or Zone Trigger for Stable Trace Holdoff set > widest pulse; Or Zone drawn and defined where unstable Basic Trigger in VSA Trigger happens when input signal crosses a voltage threshold Slope specified Holdoff set to be a longer time than the longest pulse Zone trigger Time holdoff trigger set in scope or VSA Alternative is to use Zone triggering --- define area where signal trace ignored if the trace passes through Trigger limited compared to the vector signal analyzer Scope capture in VSA AD Symposium Page 19

20 Agenda Concept for Radar/Pulse signal analysis Characteristics of Radar/Pulse signal Measurement considerations AD Symposium Page 20 Overcome challenges of complex pulse analysis How to identify the signal immediately? How to acquire wideband signal with best fidelity? How to improve acquisition efficiency? How to characterize pulse modulation? Summary

greater than 500 MHz Frequency hopping happens in wide

21 How to Acquire a Wideband Signal with the Best Fidelity? Wideband Acquisition Requirement UWB Radar bandwidth greater than 500 MHz Frequency hopping happens in wide range Wideband acquisition for EW/SIGINT AD Symposium Page 21

22 How to Acquire a Wideband Signal with the Best Fidelity? Dynamic Range in Wideband Acquisition Dynamic range is critical in: - Out-band distortion search - Dynamic environment with large and small signals Dynamic range is limited in wideband acquisition due to: - Noise level increase as BW increase - ADC effective bits limited for high sample rate Trade-off between BW & DR AD Symposium Page 22

in sweep mode - Too narrow for wideband vector analysis Signal analyzer is now increasing BW with high DR - 510 MHz BW with 2.

23 >78 dbc How to Acquire Wideband Signal with the Best Fidelity? Signal Analyzers pursuing wider BW with high DR Signal analyzer was narrow BW instrument with high DR - Spectrum monitoring in sweep mode - Too narrow for wideband vector analysis Signal analyzer is now increasing BW with high DR MHz BW with 2.4 GSa/s sample rate - >78 dbc SFDR with 14 bit ADC 1.8 GHz fundamental New proprietary ADC 2.4G Sa/s 14 bit 510 MHz span and analysis BW UXA FFT with 1.8 GHz sine input. AD Symposium Page 23

24 >70 dbc How to Acquire Wideband Signal with the Best Fidelity? Oscilloscopes pursue high DR with wide BW Oscilloscopes increase frequency and BW coverage to 63 GHz A view of 500 MHz analysis bandwidth measurement with S-Series 8 GHz BW scope 500 MHz span selected in VSA as in previous UXA example 30 khz resolution bandwidth 10 averages 1.8 GHz fundamental 500 MHz span See a 72 db SFDR with 10-bit A/D May have to navigate around oscilloscope spurs S-Series FFT Response- 1.8 GHz sine input. AD Symposium Page 24

25 >70 dbc How to Acquire Wideband Signal with the Best Fidelity? Oscilloscopes pursue high DR with wide BW 8 GHz BW S-Series SFDR shown at 72 db in 100 khz ResBW across 5 GHz span / analysis BW Noise density is optimized to midrange signal analyzer level ~ -160 dbm/hz at 2mV/div ~ 136 dbm/hz at 100 mv/div) 5 GHz span S-Series Spurious Response- 1 GHz sine input AD Symposium Page 25

26 How to Acquire a Wideband Signal with the Best Fidelity? Center 3.7GHz Span 500 MHz ResBW 200 khz 200 MHz chirp on large pulse +6 dbm range 100 averages Pulses with 60 db power difference seen with UXA signal analyzer AD Symposium Page 26

27 How to Acquire a Wideband Signal with the Best Fidelity? Center 3.7 GHz Span 500 MHz ResBW 200 khz 200 MHz chirp 6 dbm range 100 averages (same conditions as UXA) Pulses with 50 db power difference seen with S-series oscilloscope AD Symposium Page 27

28 SNR in db How to Acquire Wideband Signal with the Best Fidelity? Oscilloscope SNR is a function of the measurement bandwidth This is an example graph of expected SNR for the scope 0 dbm sensitivity range (63 mv/div) Ignoring spurs S Series SNR vs. Inst. 0dBm Range E E E E E E+10 VSA Span/Inst BW in Hz 7 ENOB ~= 42 db 8 GHz ~= 80dB 1 MHz AD Symposium Page 28

Getting Noise Density from Data Sheet V rms Noise From S-Series Data (8 GHz model) V/div dbm Ref

dbm/hz 5mV/div -24 dbm -156 dbm/hz 10mV/div -18 dbm -154 dbm/hz 20mV/div -12 dbm -150 dbm/hz

+16 dbm -124 dbm/hz 1V/div +22 dbm -118 dbm/hz http://www.coretechgroup.com/dbm_calculator.php 1.

29 Getting Noise Density from Data Sheet V rms Noise From S-Series Data (8 GHz model) V/div dbm Ref Level dbm/hz Noise 50 mv/div and 8 GHz BW 1mV/div -28 dbm -158 dbm/hz ** 2mV/div -28 dbm -158 dbm/hz 5mV/div -24 dbm -156 dbm/hz 10mV/div -18 dbm -154 dbm/hz 20mV/div -12 dbm -150 dbm/hz 50mV/div -4 dbm -143 dbm/hz 100mV/div +2 dbm -136 dbm/hz 200mV/div +6 dbm -130 dbm/hz 500mV/div +16 dbm -124 dbm/hz 1V/div +22 dbm -118 dbm/hz mv rms noise = GHz = -44 dbm 10 log (8E09) = -143 dbm/hz noise density AD Symposium Page 29

30 How to Acquire a Wideband Signal with the Best Fidelity? Oscilloscope typical RF performance affecting fidelity Stated oscilloscope typical values not guaranteed, subject to change. Oscilloscope measurement conditions and UXA DANL measurement conditions below. Sensitivity / Noise Density (1 mv/div; -38 dbm range) Power Spectral Density measurement at GHz, GHz center frequency, 500 khz span, and 3 khz RBW S-Series Typical Values (tested to 8 GHz BW on a test oscilloscope unless noted) V-Series Typical Values (tested to 30 GHz on a test oscilloscope unless noted) -160 dbm/hz -159 dbm/hz UXA Signal Analyzer (Typical values) DANL (UXA log average 0 db input attenuation, 1 Hz RBW, preamp on) -166 dbm (w/ NFE off) -171 dbm (w/ NFE on) Noise Figure (derived from measurement above) 14 db 15 db 10.3 db / 5.3 db Signal to Noise Ratio / Dynamic Range (0 dbm 1 GHz input 108 db 111 db 118 db (1.8 GHz input sine, carrier, 0 dbm scope input range) 1kHz RBW) 1 GHz center frequency, 100 MHz span, 1 khz RBW, measurement at +20 MHz from center Absolute amplitude accuracy (5 oscilloscopes, 4 channels each, data points referenced to leveled RF source at each frequency point, GHz S-Series, 0-30 GHz V-Series) Deviation from linear phase (fast step input to oscilloscope, +/- 1 db (0 to 7.5 GHz) +/- 0.5 db (0 to 30 GHz) +/ db (10 MHz to 3.6 GHz, attenuation 10 db, 95 th percentile, 2 sigma) 3.4 deg (pk-pk 510 MHz BW) phase FFT calculated from derivative of the step response) +/- 7 deg +/- 3 deg Phase noise (@ 1 GHz) 10 KHz offset -121 dbc/hz -125 dbc/hz -136 dbc/hz 100 KHz offset -122 dbc/hz -131 dbc/hz -142 dbc/hz Spur Free Dynamic Range (SFDR) 1 GHz, 0 dbm signal present at input, FFT =5 GHz span, 3 GHz center, 100 khz RBW; ignoring 2 nd 5 th harmonics 72 db 67 db >78 dbc for 510 MHz BW Input Match (S11) (< 50 mv/div 0-7 GHz S-Series, 0-30 GHz V-Series) (> =50mV/div 0 7 GHz S-Series, 0-30 GHz V-Series) -15 db; 1.4 VSWR -21 db; 1.2 VSWR -15 db; 1.4 VSWR -19 db; 1.25 VSWR (10 db input attenuator) 1.1 VSWR (up to 3.6 GHz) 1.28 VSWR ( GHz) AD Symposium Page 30

31 How to Acquire a Wideband Signal with the Best Fidelity? Bandwidth scalable for pulse analysis Which platform should I choose? UXA signal analyzer 510 MHz BW, 14 bits For BW less than 510 MHz, signal analyzer should be a good choice - Frequency coverage from RF to MW - Best dynamic range and noise level For BW greater than 510 MHz, oscilloscope is the major platform - Also good for < 510 MHz, low cost, but watch throughput Signal analyzer could be combined with oscilloscope as economy solution for higher carrier and wide BW S-Series oscilloscopes 8 GHz BW, 10 bits + signal analyzer + oscilloscope 1.2 GHz BW, 10 bits AD Symposium Page 31

32 Agenda Concept for Radar/Pulse signal analysis Characteristics of Radar/Pulse signal Measurement considerations AD Symposium Page 32 Overcome challenges of complex pulse analysis How to identify the signal immediately? How to acquire wideband signal with best fidelity? How to improve acquisition efficiency? How to characterize pulse modulation? Summary

Memory size - Sample rate Captured data could be streaming to external storage

33 How to Improve Acquisition Efficiency? Capture length with wideband signal For gapless capture, the time length depends on - Memory size - Sample rate Captured data could be streaming to external storage Captured data could also be stored inside instruments for playback and post analysis Start Time Analysis Position Stop Time AD Symposium Page 33

34 How to Improve Acquisition Efficiency? Example 1: Chirp signal at 4.9 GHz CF, 500 MHz BW, 1 µs pulse width, 50 µs PRI Capture Length with UXA UXA down-converted signal to IF and digitized: - Sample Rate: 500 M*1.28=640 MSa/s - Memory Size: 536 MSa - Max Capture Length: 536 M/640 M = s Number of pulses included: s/50us = 16,750 pulses Capture length is acceptable for most cases Capture Length with S-Series Scope Oscilloscopes digitize signal at RF directly: - Sample Rate: 20 GSa/s - Memory Size: 500 MSa used in VSA - Max Capture Length: 500 M/20 G = 0.025s Number of pulses included: s/50 µs = 500 pulses Capture length is not sufficient for some cases Question: How can I capture more pulses with scopes? AD Symposium Page 34

35 How to Improve Acquisition Efficiency? Answer: Segmented Capture!! Segmented Capture Capture pulse ON period only and ignore OFF period Memory is fully used especially for low duty cycle pulses, without losing information Segmented Capture Length with S-Series Scope Segment definition: Example: Chirp signal at 4.9 GHz CF, - Segment Length: 1.2µs 500 MHz BW, 1 µs pulse width, 50 µs PRI - Sample Rate: 20G Sa/s - Size Per Segment: (20G Sa/s) * (1.2µs) = 24,000 samples - Number of Segment: (400M Sa) / (24k Sa) = 16,666 segments - Max Capture Length: 50µs * 16,666 =0.8 s - Number of pulses included: 0.8s / 50µs = 16,662 pulses Capture Length is much longer than gapless capture with scopes The Lower duty cycle the pulse has, the more benefit we get AD Symposium Page 35

36 Oscilloscope Segmented Memory RF Pulse Capture Video Demo can be found at: AD Symposium Page 37

Envelope, Frequency Trend, and Wide FFT Measurements 1 GHz wide chirp example using 5 scope functions Meas Trend of Clock TIE to see inverse of phase shift Video demo on DVD Time view of single RF

37 Envelope, Frequency Trend, and Wide FFT Measurements 1 GHz wide chirp example using 5 scope functions Meas Trend of Clock TIE to see inverse of phase shift Video demo on DVD Time view of single RF pulse in pulse train Meas Trend of Frequency to see frequency shift across the RF pulse (1 GHz linear shift) 2 GHz FFT of an RF pulse (variety of FFT window options) Example: 1 usec wide RF pulses, linear FM 3.5 GHz to 4.5 GHz, 10 usec PRI Can also make RF pulse envelope measurements AD Symposium Page 38

38 Agenda Concept for Radar/Pulse signal analysis Characteristics of Radar/Pulse signal Measurement considerations AD Symposium Page 39 Overcome challenges of complex pulse analysis How to identify the signal immediately? How to acquire wideband signal with best fidelity? How to improve acquisition efficiency? How to characterize pulse modulation? Summary

39 How to Characterize Pulse Modulation? We already have several helpful tools. Basic vector Measurement in Scope (above) and VSA (below) Spectrum monitoring with 510 MHz RTSA AD Symposium Page 40

40 How to Characterize Pulse Modulation? But still need powerful weapon for in-depth characterizing Pulse analysis features in VSA Multiple HW support with scalable analysis bandwidth & dynamic range Measures all relevant parameters including time, level and modulations Trend and histogram analysis over many pulses Works with scope segmented memory! AD Symposium Page 41

41 How to Characterize Pulse Modulation? Level measurement Pulse detection threshold definition - Isolate pulses from noise and interfering Pulse Level Results - Top Power/Base Power - Droop - Overshoot - Ripple AD Symposium Page 42

results - Pulse Width - PRI/Duty Cycle -

42 How to Characterize Pulse Modulation? Time domain measurement Pulse width detection threshold definition - Specify pulse width detection range Time domain results - Pulse Width - PRI/Duty Cycle - Rise Time/Fall Time - Ripple AD Symposium Page 43

43 How to Characterize Pulse Modulation? Frequency/phase measurement Graphical trace for Frequency vs. Time, Phase vs. Time Overlay display of traces AD Symposium Page 44

44 How to Characterize Pulse Modulation? In-pulse modulation measurement CW/LFM supported now FM Dev, Slope and In-linearity measurement for LFM Measured FM LFM Best-fit Pk-Pk Deviation (Hz) FM Error Peak (Hz) AD Symposium Page 45

Graphical histogram Measurement pause enable Perform conditional logic

45 How to Characterize Pulse Modulation? Trend and histogram analysis Pulse cumulative statistics table Graphical histogram Measurement pause enable Perform conditional logic test on a supported metrics in Pulse Table Trend Line Trace Plots Pulse modulation histogram AD Symposium Page 46

46 How to Characterize Pulse Modulation? Multi-Channel or Multi-Format Analysis in Parallel Chirp Pulse at 2.3 GHz + LTE signal at 2.36 GHz AD Symposium Page 47

47 2 Minute Video of VSA Version 19 Pulse Option BHG Using oscilloscope segmented memory for long capture time Video Demo can be found at AD Symposium Page 48

48 How to Characterize Pulse Modulation? The Pulse Analysis feature in VSA is helpful for ALL Pulse Designers Testing Tx and components Pulse modulation stability Characterizing threats (SIGINT) Verifying threat simulations Verifying EW jamming responses Transmitter Interference Target Target with EW Radar Receiver Clutter Jamming or Deception EW AD Symposium Page 49

49 Agenda Concept for Radar/Pulse signal analysis Characteristics of Radar/Pulse signal Measurement considerations AD Symposium Page 50 Overcome challenges of complex pulse analysis How to identify the signal immediately? How to acquire wideband signal with best fidelity? How to improve acquisition efficiency? How to characterize pulse modulation? Summary

50 Summary Real-time trigger in Magnitude, Frequency and Time domain is the first step for successful pulse analysis (in SA) Although lacking such triggers, new oscilloscopes offer impressive RF performance useful for in-band measurements Complex Radar/EW environment requires wider acquisition bandwidth with higher dynamic range Acquisition efficiency could be improved significantly with segmented capture Pulse analysis feature in VSA can provide complete pulse measurements in multiple views AD Symposium Page 51

51 Demo Videos Available on the AD Symposium DVD Basic oscilloscope FFT measurements on a sine wave input Oscilloscope wideband RF pulse time domain analysis on pulse envelope, display of linear FM chirp across pulse, and use of segmented memory for long capture time Oscilloscope wideband RF pulse frequency domain analysis with FFTs, gated FFTs, and segmented memory Oscilloscope wideband RF pulse analysis on envelope, display of linear FM chirp across pulse and unwrapped phase across pulse Oscilloscope VSA pulse option for automated RF pulse time and frequency domain analysis adjust number of segments and statistical measurements Oscilloscope VSA pulse option for automated RF pulse time and frequency domain analysis with segmented memory Oscilloscope VSA for wideband communications signal analysis AD Symposium Page 52

52 Questions? AD Symposium Page 53

RF Measurements You Didn't Know Your Oscilloscope Could Make

RF Measurements You Didn't Know Your Oscilloscope Could Make January 21, 2015 Brad Frieden Product Manager Keysight Technologies Agenda RF Measurements using an oscilloscope (30 min) When to use an Oscilloscope